<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>T-测试</title>
    <style>
        html {
            scroll-behavior: smooth;
        }
        body {
            margin: 0;
        }
        .unint {
            height: 100vh;
            width: 100%;
            position: sticky;
            top: 0;
            background-color: lightcyan;
        }
        .box1 {
            height: 100px;
            width: 180px;
            border: 2px crimson solid;
        }
        .box2 {
            height: 90px;
            width: 90px;
            border: 2px rgb(125, 115, 255) solid;
        }
        #tip {
            background-color: cadetblue;
        }
    </style>
</head>
<body>
    <div class="unint">
        <a href="#tip">Go</a>
    </div>
    <div class="unint" id="tip">
        <div class="box2"></div>
        <div class="box1"></div><div class="box1"></div>
    </div>
    <div class="unint">
        <ol>
            <li>Button</li>
            <li><a href="#">Go top</a></li>
        </ol>
    </div>
</body>
</html>